1. Field of the Invention
The present invention concerns the preparation of novel curable, ethylenically unsaturated polymers formed by reacting a polycarbodiimide having free isocyanate groups with compounds having active hydrogens and copolymerizable ethylenic unsaturation. The ethylenically unsaturated, active hydrogen compounds can be partially replaced with saturated compounds.
2. Description of the Prior Art
Vinyl copolymerizable thermosetting resins are in widespread commercial use. Of special interest are those resins, which are capable of rapid cure, and which have outstanding physical and thermal properties.
Most commercially available resins are products of polyester or epoxy chemistry. In general, the preparation of these resins requires high temperatures, several process steps, and long processing time.
U.S. Pat. No. 4,148,844 to von Bonin et al, discloses casting resins consisting of a mixture of polycarbodiimides in vinyl monomers which cure by heating to a temperature above 40.degree. C. The polycarbodiimides are prepared by reacting polyfunctional or monofunctional isocyanates with a phospholane oxide catalyst. The unreacted or free terminal isocyanate groups of the resulting polycarbodiimides can be eliminated by reaction with an amine or alcohol.
U.S. Pat. No. 4,463,158 to O'Connor et al discloses a liquid polymer composition which comprises a modified polyurethane oligomer containing ethylenic unsaturation and a free radical generating catalyst. The polyurethane oligomer is prepared by reacting an organic polyisocyanate with an isocyanate reactive group containing unsaturated monomer to obtain an isocyanate-terminated prepolymer of controlled molecular weight having a free isocyanate content of from about 0.5% to about 30%. The isocyanate-terminated prepolymer is then reacted with a polyol to produce a polyurethane oligomer of controlled molecular weight with terminal reactive unsaturation.
U.S. Pat. No. 4,367,302 to Le Roy et al discloses crosslinkable thermoplastic polyurethanes having isocyanate end groups and containing ethylenic side groups. These polyurethanes are obtained by reacting an organic diisocyanate with a saturated diol and an unsaturated diol. The ethylenic side groups in the polyurethane product are branched over the entire whole length of the linear skeleton of the polyurethane molecule.
U.S. Pat. No. 4,758,625 to Boyack et al discloses urethane crosslinked acrylic coatings. The polymer backbone exhibits the basic characteristics of acrylic polymers and contains at least 50% by weight of acrylic monomer.
U.S. Pat. No. 4,028,310 to Shafer et al relates to the preparation of polyisocyanate containing acylurea groups and, optionally, carbodiimide groups in the polyisocyanate polyaddition reaction carried out in the presence of diamine chain extenders.
U.S. Pat. No. 4,077,989 to Shafer et al relates to the production of modified isocyanates wherein compounds containing isocyanate and carbodiimide groups are reacted with carboxylic acids.
U.S. Pat. No. 4,174,433 and U.S. Pat. No. 4,192,925, both to Shafer et al, relate to polyols modified by guanidine groups, which are used as starting components for the preparation of polyurethane plastics.
U.S. Pat. No. 4,192,926 to Shafer et al relates to polyols modified by acylurea groups used as starting components in the preparation of foamed polyurethane plastics.
U.S. Pat. No. 4,192,927 to Shafer et al relates to polyols modified by phosphonoformamidine groups, for use as a starting component in the preparation of foamed polyurethane plastics.
U.S. Pat. No. 4,321,394 to Shafer et al relates to a process for producing addition compounds of compounds containing hydroxyl groups and carbodiimides substantially free from isocyanate groups, by reacting the components in the presence of an inorganic or organic tin compound used as the catalyst.
Ulrich et al, Journal of Cellular Plastics, September-October 1985, pages 350 to 357 reviews the chemistry and properties of low density polycarbodiimide foams and discloses suitable formulations, processing conditions, physical properties and small scale flame test results of the resultant polymers.
Williams et al, "Carbodiimide Chemistry: Recent Advances", Chem. Rev., Vol. 81, pages 589 to 636 (American Chemical Society 1981) is a comprehensive literature review of carbodiimide chemistry covering synthesis, structure and physical properties, chemical properties, metal insertion reactions, formation of heterocycles, carbodiimides in biological and polymer chemistry, and their application in photography, dyeing and related subjects, and analysis.
Kurzer et al, "Advances in the Chemistry of Carbodiimides", Chemical Reviews, Vol. 67, No. 2, pages 107 to 152 (Mar. 27, 1967) reviews carbodiimide chemistry including synthesis, physical properties, structure, chemical properties and various carbodiimide compositions.
Wagner et al, "Alpha, Omega-Diisocyanatocarbodiimides, Polycarbodiimides, and Their Derivatives", Angewandte Chemie (International edition in English), Vol. 20, No. 10, pages 819-898 (October 1981) discusses the synthesis and properties of these carbodiimides and various reactions particularly the in situ production of polycarbodiimides via matrix reactions in flexible polyurethane foams.
Khorana, "The Chemistry of Carbodiimides", Chemical Reviews, Vol. 53, pages 145 to 166 (1953) is a review article covering the preparation and properties of carbodiimides, as well as base catalyzed addition reactions and comparison of carbodiimides with similar systems.